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Simplify the way jobs work and drop the persist type, so all jobs are
fire-and-forget.

Status jobs now managed with two trees of output (new and old), rather
than storing the output in the jobs themselves. When the status line is
processed any jobs which don't appear in the new tree are started and
the output from the old tree displayed. When a job finishes it updates
the new tree with its output and that is used for any subsequent
redraws. When the status interval expires, the new tree is moved to the
old so that all jobs are run again.

This fixes the "#(echo %H:%M:%S)" problem which would lead to thousands
of identical persistent jobs and high memory use (this can still be
achieved by adding "sleep 30" but that is much less likely to happen by
accident).

/* $OpenBSD: server-client.c,v 1.51 2011/01/26 01:54:56 nicm Exp $ */

/*
 * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <event.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <paths.h>
#include <unistd.h>

#include "tmux.h"

void	server_client_handle_key(int, struct mouse_event *, void *);
void	server_client_repeat_timer(int, short, void *);
void	server_client_check_exit(struct client *);
void	server_client_check_backoff(struct client *);
void	server_client_check_redraw(struct client *);
void	server_client_set_title(struct client *);
void	server_client_reset_state(struct client *);
void	server_client_in_callback(struct bufferevent *, short, void *);
void	server_client_out_callback(struct bufferevent *, short, void *);
void	server_client_err_callback(struct bufferevent *, short, void *);

int	server_client_msg_dispatch(struct client *);
void	server_client_msg_command(struct client *, struct msg_command_data *);
void	server_client_msg_identify(
	    struct client *, struct msg_identify_data *, int);
void	server_client_msg_shell(struct client *);

void printflike2 server_client_msg_error(struct cmd_ctx *, const char *, ...);
void printflike2 server_client_msg_print(struct cmd_ctx *, const char *, ...);
void printflike2 server_client_msg_info(struct cmd_ctx *, const char *, ...);

/* Create a new client. */
void
server_client_create(int fd)
{
	struct client	*c;
	u_int		 i;

	setblocking(fd, 0);

	c = xcalloc(1, sizeof *c);
	c->references = 0;
	imsg_init(&c->ibuf, fd);
	server_update_event(c);

	if (gettimeofday(&c->creation_time, NULL) != 0)
		fatal("gettimeofday failed");
	memcpy(&c->activity_time, &c->creation_time, sizeof c->activity_time);

	c->stdin_event = NULL;
	c->stdout_event = NULL;
	c->stderr_event = NULL;

	c->tty.fd = -1;
	c->title = NULL;

	c->session = NULL;
	c->last_session = NULL;
	c->tty.sx = 80;
	c->tty.sy = 24;

	screen_init(&c->status, c->tty.sx, 1, 0);
	RB_INIT(&c->status_new);
	RB_INIT(&c->status_old);

	c->message_string = NULL;
	ARRAY_INIT(&c->message_log);

	c->prompt_string = NULL;
	c->prompt_buffer = NULL;
	c->prompt_index = 0;

	evtimer_set(&c->repeat_timer, server_client_repeat_timer, c);

	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
		if (ARRAY_ITEM(&clients, i) == NULL) {
			ARRAY_SET(&clients, i, c);
			return;
		}
	}
	ARRAY_ADD(&clients, c);
	log_debug("new client %d", fd);
}

/* Lost a client. */
void
server_client_lost(struct client *c)
{
	struct message_entry	*msg;
	u_int			 i;

	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
		if (ARRAY_ITEM(&clients, i) == c)
			ARRAY_SET(&clients, i, NULL);
	}
	log_debug("lost client %d", c->ibuf.fd);

	/*
	 * If CLIENT_TERMINAL hasn't been set, then tty_init hasn't been called
	 * and tty_free might close an unrelated fd.
	 */
	if (c->flags & CLIENT_TERMINAL)
		tty_free(&c->tty);

	if (c->stdin_fd != -1) {
		setblocking(c->stdin_fd, 1);
		close(c->stdin_fd);
	}
	if (c->stdin_event != NULL)
		bufferevent_free(c->stdin_event);
	if (c->stdout_fd != -1) {
		setblocking(c->stdout_fd, 1);
		close(c->stdout_fd);
	}
	if (c->stdout_event != NULL)
		bufferevent_free(c->stdout_event);
	if (c->stderr_fd != -1) {
		setblocking(c->stderr_fd, 1);
		close(c->stderr_fd);
	}
	if (c->stderr_event != NULL)
		bufferevent_free(c->stderr_event);

	status_free_jobs(&c->status_new);
	status_free_jobs(&c->status_old);
	screen_free(&c->status);

	if (c->title != NULL)
		xfree(c->title);

	evtimer_del(&c->repeat_timer);

	evtimer_del(&c->identify_timer);

	if (c->message_string != NULL)
		xfree(c->message_string);
	evtimer_del(&c->message_timer);
	for (i = 0; i < ARRAY_LENGTH(&c->message_log); i++) {
		msg = &ARRAY_ITEM(&c->message_log, i);
		xfree(msg->msg);
	}
	ARRAY_FREE(&c->message_log);

	if (c->prompt_string != NULL)
		xfree(c->prompt_string);
	if (c->prompt_buffer != NULL)
		xfree(c->prompt_buffer);

	if (c->cwd != NULL)
		xfree(c->cwd);

	close(c->ibuf.fd);
	imsg_clear(&c->ibuf);
	event_del(&c->event);

	for (i = 0; i < ARRAY_LENGTH(&dead_clients); i++) {
		if (ARRAY_ITEM(&dead_clients, i) == NULL) {
			ARRAY_SET(&dead_clients, i, c);
			break;
		}
	}
	if (i == ARRAY_LENGTH(&dead_clients))
		ARRAY_ADD(&dead_clients, c);
	c->flags |= CLIENT_DEAD;

	recalculate_sizes();
	server_check_unattached();
	server_update_socket();
}

/* Process a single client event. */
void
server_client_callback(int fd, short events, void *data)
{
	struct client	*c = data;

	if (c->flags & CLIENT_DEAD)
		return;

	if (fd == c->ibuf.fd) {
		if (events & EV_WRITE && msgbuf_write(&c->ibuf.w) < 0)
			goto client_lost;

		if (c->flags & CLIENT_BAD) {
			if (c->ibuf.w.queued == 0)
				goto client_lost;
			return;
		}

		if (events & EV_READ && server_client_msg_dispatch(c) != 0)
			goto client_lost;
	}

	server_update_event(c);
	return;

client_lost:
	server_client_lost(c);
}

/* Handle client status timer. */
void
server_client_status_timer(void)
{
	struct client	*c;
	struct session	*s;
	struct timeval	 tv;
	u_int		 i;
	int		 interval;
	time_t		 difference;

	if (gettimeofday(&tv, NULL) != 0)
		fatal("gettimeofday failed");

	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
		c = ARRAY_ITEM(&clients, i);
		if (c == NULL || c->session == NULL)
			continue;
		if (c->message_string != NULL || c->prompt_string != NULL) {
			/*
			 * Don't need timed redraw for messages/prompts so bail
			 * now. The status timer isn't reset when they are
			 * redrawn anyway.
			 */
			continue;
		}
		s = c->session;

		if (!options_get_number(&s->options, "status"))
			continue;
		interval = options_get_number(&s->options, "status-interval");

		difference = tv.tv_sec - c->status_timer.tv_sec;
		if (difference >= interval) {
			status_update_jobs(c);
			c->flags |= CLIENT_STATUS;
		}
	}
}

/* Handle data key input from client. */
void
server_client_handle_key(int key, struct mouse_event *mouse, void *data)
{
	struct client		*c = data;
	struct session		*s;
	struct window		*w;
	struct window_pane	*wp;
	struct options		*oo;
	struct timeval		 tv;
	struct key_binding	*bd;
	struct keylist		*keylist;
	int		      	 xtimeout, isprefix;
	u_int			 i;

	/* Check the client is good to accept input. */
	if ((c->flags & (CLIENT_DEAD|CLIENT_SUSPENDED)) != 0)
		return;
	if (c->session == NULL)
		return;
	s = c->session;

	/* Update the activity timer. */
	if (gettimeofday(&c->activity_time, NULL) != 0)
		fatal("gettimeofday failed");
	memcpy(&s->activity_time, &c->activity_time, sizeof s->activity_time);

	w = c->session->curw->window;
	wp = w->active;
	oo = &c->session->options;

	/* Special case: number keys jump to pane in identify mode. */
	if (c->flags & CLIENT_IDENTIFY && key >= '0' && key <= '9') {
		if (c->flags & CLIENT_READONLY)
			return;
		wp = window_pane_at_index(w, key - '0');
		if (wp != NULL && window_pane_visible(wp))
			window_set_active_pane(w, wp);
		server_clear_identify(c);
		return;
	}

	/* Handle status line. */
	if (!(c->flags & CLIENT_READONLY)) {
		status_message_clear(c);
		server_clear_identify(c);
	}
	if (c->prompt_string != NULL) {
		if (!(c->flags & CLIENT_READONLY))
			status_prompt_key(c, key);
		return;
	}

	/* Check for mouse keys. */
	if (key == KEYC_MOUSE) {
		if (c->flags & CLIENT_READONLY)
			return;
		if (options_get_number(oo, "mouse-select-pane")) {
			window_set_active_at(w, mouse->x, mouse->y);
			server_redraw_window_borders(w);
			wp = w->active;
		}
		window_pane_mouse(wp, c->session, mouse);
		return;
	}

	/* Is this a prefix key? */
	keylist = options_get_data(&c->session->options, "prefix");
	isprefix = 0;
	for (i = 0; i < ARRAY_LENGTH(keylist); i++) {
		if (key == ARRAY_ITEM(keylist, i)) {
			isprefix = 1;
			break;
		}
	}

	/* No previous prefix key. */
	if (!(c->flags & CLIENT_PREFIX)) {
		if (isprefix)
			c->flags |= CLIENT_PREFIX;
		else {
			/* Try as a non-prefix key binding. */
			if ((bd = key_bindings_lookup(key)) == NULL) {
				if (!(c->flags & CLIENT_READONLY))
					window_pane_key(wp, c->session, key);
			} else
				key_bindings_dispatch(bd, c);
		}
		return;
	}

	/* Prefix key already pressed. Reset prefix and lookup key. */
	c->flags &= ~CLIENT_PREFIX;
	if ((bd = key_bindings_lookup(key | KEYC_PREFIX)) == NULL) {
		/* If repeating, treat this as a key, else ignore. */
		if (c->flags & CLIENT_REPEAT) {
			c->flags &= ~CLIENT_REPEAT;
			if (isprefix)
				c->flags |= CLIENT_PREFIX;
			else if (!(c->flags & CLIENT_READONLY))
				window_pane_key(wp, c->session, key);
		}
		return;
	}

	/* If already repeating, but this key can't repeat, skip it. */
	if (c->flags & CLIENT_REPEAT && !bd->can_repeat) {
		c->flags &= ~CLIENT_REPEAT;
		if (isprefix)
			c->flags |= CLIENT_PREFIX;
		else if (!(c->flags & CLIENT_READONLY))
			window_pane_key(wp, c->session, key);
		return;
	}

	/* If this key can repeat, reset the repeat flags and timer. */
	xtimeout = options_get_number(&c->session->options, "repeat-time");
	if (xtimeout != 0 && bd->can_repeat) {
		c->flags |= CLIENT_PREFIX|CLIENT_REPEAT;

		tv.tv_sec = xtimeout / 1000;
		tv.tv_usec = (xtimeout % 1000) * 1000L;
		evtimer_del(&c->repeat_timer);
		evtimer_add(&c->repeat_timer, &tv);
	}

	/* Dispatch the command. */
	key_bindings_dispatch(bd, c);
}

/* Client functions that need to happen every loop. */
void
server_client_loop(void)
{
	struct client		*c;
	struct window		*w;
	struct window_pane	*wp;
	u_int		 	 i;

	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
		c = ARRAY_ITEM(&clients, i);
		if (c == NULL)
			continue;

		server_client_check_exit(c);
		if (c->session != NULL) {
			server_client_check_redraw(c);
			server_client_reset_state(c);
		}
	}

	/*
	 * Any windows will have been redrawn as part of clients, so clear
	 * their flags now.
	 */
	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
		w = ARRAY_ITEM(&windows, i);
		if (w == NULL)
			continue;

		w->flags &= ~WINDOW_REDRAW;
		TAILQ_FOREACH(wp, &w->panes, entry)
			wp->flags &= ~PANE_REDRAW;
	}
}

/*
 * Update cursor position and mode settings. The scroll region and attributes
 * are cleared when idle (waiting for an event) as this is the most likely time
 * a user may interrupt tmux, for example with ~^Z in ssh(1). This is a
 * compromise between excessive resets and likelihood of an interrupt.
 *
 * tty_region/tty_reset/tty_update_mode already take care of not resetting
 * things that are already in their default state.
 */
void
server_client_reset_state(struct client *c)
{
	struct window		*w = c->session->curw->window;
	struct window_pane	*wp = w->active;
	struct screen		*s = wp->screen;
	struct options		*oo = &c->session->options;
	int			 status, mode;

	tty_region(&c->tty, 0, c->tty.sy - 1);

	status = options_get_number(oo, "status");
	if (!window_pane_visible(wp) || wp->yoff + s->cy >= c->tty.sy - status)
		tty_cursor(&c->tty, 0, 0);
	else
		tty_cursor(&c->tty, wp->xoff + s->cx, wp->yoff + s->cy);

	/*
	 * Any mode will do for mouse-select-pane, but set standard mode if
	 * none.
	 */
	mode = s->mode;
	if (TAILQ_NEXT(TAILQ_FIRST(&w->panes), entry) != NULL &&
	    options_get_number(oo, "mouse-select-pane") &&
	    (mode & ALL_MOUSE_MODES) == 0)
		mode |= MODE_MOUSE_STANDARD;

	/*
	 * Set UTF-8 mouse input if required. If the terminal is UTF-8, the
	 * user has set mouse-utf8 and any mouse mode is in effect, turn on
	 * UTF-8 mouse input. If the receiving terminal hasn't requested it
	 * (that is, it isn't in s->mode), then it'll be converted in
	 * input_mouse.
	 */
	if ((c->tty.flags & TTY_UTF8) &&
	    (mode & ALL_MOUSE_MODES) && options_get_number(oo, "mouse-utf8"))
		mode |= MODE_MOUSE_UTF8;
	else
		mode &= ~MODE_MOUSE_UTF8;

	/* Set the terminal mode and reset attributes. */
	tty_update_mode(&c->tty, mode);
	tty_reset(&c->tty);
}

/* Repeat time callback. */
/* ARGSUSED */
void
server_client_repeat_timer(unused int fd, unused short events, void *data)
{
	struct client	*c = data;

	if (c->flags & CLIENT_REPEAT)
		c->flags &= ~(CLIENT_PREFIX|CLIENT_REPEAT);
}

/* Check if client should be exited. */
void
server_client_check_exit(struct client *c)
{
	struct msg_exit_data	exitdata;

	if (!(c->flags & CLIENT_EXIT))
		return;

	if (c->stdout_fd != -1 && c->stdout_event != NULL &&
	    EVBUFFER_LENGTH(c->stdout_event->output) != 0)
		return;
	if (c->stderr_fd != -1 && c->stderr_event != NULL &&
	    EVBUFFER_LENGTH(c->stderr_event->output) != 0)
		return;

	exitdata.retcode = c->retcode;
	server_write_client(c, MSG_EXIT, &exitdata, sizeof exitdata);

	c->flags &= ~CLIENT_EXIT;
}

/*
 * Check if the client should backoff. During backoff, data from external
 * programs is not written to the terminal. When the existing data drains, the
 * client is redrawn.
 *
 * There are two backoff phases - both the tty and client have backoff flags -
 * the first to allow existing data to drain and the latter to ensure backoff
 * is disabled until the redraw has finished and prevent the redraw triggering
 * another backoff.
 */
void
server_client_check_backoff(struct client *c)
{
	struct tty	*tty = &c->tty;
	size_t		 used;

	used = EVBUFFER_LENGTH(tty->event->output);

	/*
	 * If in the second backoff phase (redrawing), don't check backoff
	 * until the redraw has completed (or enough of it to drop below the
	 * backoff threshold).
	 */
	if (c->flags & CLIENT_BACKOFF) {
		if (used > BACKOFF_THRESHOLD)
			return;
		c->flags &= ~CLIENT_BACKOFF;
		return;
	}

	/* Once drained, allow data through again and schedule redraw. */
	if (tty->flags & TTY_BACKOFF) {
		if (used != 0)
			return;
		tty->flags &= ~TTY_BACKOFF;
		c->flags |= (CLIENT_BACKOFF|CLIENT_REDRAWWINDOW|CLIENT_STATUS);
		return;
	}

	/* If too much data, start backoff. */
	if (used > BACKOFF_THRESHOLD)
		tty->flags |= TTY_BACKOFF;
}

/* Check for client redraws. */
void
server_client_check_redraw(struct client *c)
{
	struct session		*s = c->session;
	struct window_pane	*wp;
	int		 	 flags, redraw;

	flags = c->tty.flags & TTY_FREEZE;
	c->tty.flags &= ~TTY_FREEZE;

	if (c->flags & (CLIENT_REDRAW|CLIENT_STATUS)) {
		if (options_get_number(&s->options, "set-titles"))
			server_client_set_title(c);

		if (c->message_string != NULL)
			redraw = status_message_redraw(c);
		else if (c->prompt_string != NULL)
			redraw = status_prompt_redraw(c);
		else
			redraw = status_redraw(c);
		if (!redraw)
			c->flags &= ~CLIENT_STATUS;
	}

	if (c->flags & CLIENT_REDRAW) {
		screen_redraw_screen(c, 0, 0);
		c->flags &= ~(CLIENT_STATUS|CLIENT_BORDERS);
	} else if (c->flags & CLIENT_REDRAWWINDOW) {
		TAILQ_FOREACH(wp, &c->session->curw->window->panes, entry)
			screen_redraw_pane(c, wp);
		c->flags &= ~CLIENT_REDRAWWINDOW;
	} else {
		TAILQ_FOREACH(wp, &c->session->curw->window->panes, entry) {
			if (wp->flags & PANE_REDRAW)
				screen_redraw_pane(c, wp);
		}
	}

	if (c->flags & CLIENT_BORDERS)
		screen_redraw_screen(c, 0, 1);

	if (c->flags & CLIENT_STATUS)
		screen_redraw_screen(c, 1, 0);

	c->tty.flags |= flags;

	c->flags &= ~(CLIENT_REDRAW|CLIENT_STATUS|CLIENT_BORDERS);
}

/* Set client title. */
void
server_client_set_title(struct client *c)
{
	struct session	*s = c->session;
	const char	*template;
	char		*title;

	template = options_get_string(&s->options, "set-titles-string");

	title = status_replace(c, NULL, template, time(NULL), 1);
	if (c->title == NULL || strcmp(title, c->title) != 0) {
		if (c->title != NULL)
			xfree(c->title);
		c->title = xstrdup(title);
		tty_set_title(&c->tty, c->title);
	}
	xfree(title);
}

/*
 * Error callback for client stdin. Caller must increase reference count when
 * enabling event!
 */
void
server_client_in_callback(
    unused struct bufferevent *bufev, unused short what, void *data)
{
	struct client	*c = data;

	c->references--;
	if (c->flags & CLIENT_DEAD)
		return;

	bufferevent_disable(c->stdin_event, EV_READ|EV_WRITE);
	setblocking(c->stdin_fd, 1);
	close(c->stdin_fd);
	c->stdin_fd = -1;

	if (c->stdin_callback != NULL)
		c->stdin_callback(c, c->stdin_data);
}

/* Error callback for client stdout. */
void
server_client_out_callback(
    unused struct bufferevent *bufev, unused short what, unused void *data)
{
	struct client	*c = data;

	bufferevent_disable(c->stdout_event, EV_READ|EV_WRITE);
	setblocking(c->stdout_fd, 1);
	close(c->stdout_fd);
	c->stdout_fd = -1;
}

/* Error callback for client stderr. */
void
server_client_err_callback(
    unused struct bufferevent *bufev, unused short what, unused void *data)
{
	struct client	*c = data;

	bufferevent_disable(c->stderr_event, EV_READ|EV_WRITE);
	setblocking(c->stderr_fd, 1);
	close(c->stderr_fd);
	c->stderr_fd = -1;
}

/* Dispatch message from client. */
int
server_client_msg_dispatch(struct client *c)
{
	struct imsg		 imsg;
	struct msg_command_data	 commanddata;
	struct msg_identify_data identifydata;
	struct msg_environ_data	 environdata;
	ssize_t			 n, datalen;

	if ((n = imsg_read(&c->ibuf)) == -1 || n == 0)
		return (-1);

	for (;;) {
		if ((n = imsg_get(&c->ibuf, &imsg)) == -1)
			return (-1);
		if (n == 0)
			return (0);
		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;

		if (imsg.hdr.peerid != PROTOCOL_VERSION) {
			server_write_client(c, MSG_VERSION, NULL, 0);
			c->flags |= CLIENT_BAD;
			imsg_free(&imsg);
			continue;
		}

		log_debug("got %d from client %d", imsg.hdr.type, c->ibuf.fd);
		switch (imsg.hdr.type) {
		case MSG_COMMAND:
			if (datalen != sizeof commanddata)
				fatalx("bad MSG_COMMAND size");
			memcpy(&commanddata, imsg.data, sizeof commanddata);

			server_client_msg_command(c, &commanddata);
			break;
		case MSG_IDENTIFY:
			if (datalen != sizeof identifydata)
				fatalx("bad MSG_IDENTIFY size");
			if (imsg.fd == -1)
				fatalx("MSG_IDENTIFY missing fd");
			memcpy(&identifydata, imsg.data, sizeof identifydata);

			c->stdin_fd = imsg.fd;
			c->stdin_event = bufferevent_new(c->stdin_fd,
			    NULL, NULL, server_client_in_callback, c);
			if (c->stdin_event == NULL)
				fatalx("failed to create stdin event");
			setblocking(c->stdin_fd, 0);

			server_client_msg_identify(c, &identifydata, imsg.fd);
			break;
		case MSG_STDOUT:
			if (datalen != 0)
				fatalx("bad MSG_STDOUT size");
			if (imsg.fd == -1)
				fatalx("MSG_STDOUT missing fd");

			c->stdout_fd = imsg.fd;
			c->stdout_event = bufferevent_new(c->stdout_fd,
			    NULL, NULL, server_client_out_callback, c);
			if (c->stdout_event == NULL)
				fatalx("failed to create stdout event");
			setblocking(c->stdout_fd, 0);

			break;
		case MSG_STDERR:
			if (datalen != 0)
				fatalx("bad MSG_STDERR size");
			if (imsg.fd == -1)
				fatalx("MSG_STDERR missing fd");

			c->stderr_fd = imsg.fd;
			c->stderr_event = bufferevent_new(c->stderr_fd,
			    NULL, NULL, server_client_err_callback, c);
			if (c->stderr_event == NULL)
				fatalx("failed to create stderr event");
			setblocking(c->stderr_fd, 0);

			break;
		case MSG_RESIZE:
			if (datalen != 0)
				fatalx("bad MSG_RESIZE size");

			if (tty_resize(&c->tty)) {
				recalculate_sizes();
				server_redraw_client(c);
			}
			break;
		case MSG_EXITING:
			if (datalen != 0)
				fatalx("bad MSG_EXITING size");

			c->session = NULL;
			tty_close(&c->tty);
			server_write_client(c, MSG_EXITED, NULL, 0);
			break;
		case MSG_WAKEUP:
		case MSG_UNLOCK:
			if (datalen != 0)
				fatalx("bad MSG_WAKEUP size");

			if (!(c->flags & CLIENT_SUSPENDED))
				break;
			c->flags &= ~CLIENT_SUSPENDED;

			if (gettimeofday(&c->activity_time, NULL) != 0)
				fatal("gettimeofday");
			if (c->session != NULL)
				session_update_activity(c->session);

			tty_start_tty(&c->tty);
			server_redraw_client(c);
			recalculate_sizes();
			break;
		case MSG_ENVIRON:
			if (datalen != sizeof environdata)
				fatalx("bad MSG_ENVIRON size");
			memcpy(&environdata, imsg.data, sizeof environdata);

			environdata.var[(sizeof environdata.var) - 1] = '\0';
			if (strchr(environdata.var, '=') != NULL)
				environ_put(&c->environ, environdata.var);
			break;
		case MSG_SHELL:
			if (datalen != 0)
				fatalx("bad MSG_SHELL size");

			server_client_msg_shell(c);
			break;
		default:
			fatalx("unexpected message");
		}

		imsg_free(&imsg);
	}
}

/* Callback to send error message to client. */
void printflike2
server_client_msg_error(struct cmd_ctx *ctx, const char *fmt, ...)
{
	va_list	ap;

	va_start(ap, fmt);
	evbuffer_add_vprintf(ctx->cmdclient->stderr_event->output, fmt, ap);
	va_end(ap);

	bufferevent_write(ctx->cmdclient->stderr_event, "\n", 1);
	ctx->cmdclient->retcode = 1;
}

/* Callback to send print message to client. */
void printflike2
server_client_msg_print(struct cmd_ctx *ctx, const char *fmt, ...)
{
	va_list	ap;

	va_start(ap, fmt);
	evbuffer_add_vprintf(ctx->cmdclient->stdout_event->output, fmt, ap);
	va_end(ap);

	bufferevent_write(ctx->cmdclient->stdout_event, "\n", 1);
}

/* Callback to send print message to client, if not quiet. */
void printflike2
server_client_msg_info(struct cmd_ctx *ctx, const char *fmt, ...)
{
	va_list	ap;

	if (options_get_number(&global_options, "quiet"))
		return;

	va_start(ap, fmt);
	evbuffer_add_vprintf(ctx->cmdclient->stdout_event->output, fmt, ap);
	va_end(ap);

	bufferevent_write(ctx->cmdclient->stdout_event, "\n", 1);
}

/* Handle command message. */
void
server_client_msg_command(struct client *c, struct msg_command_data *data)
{
	struct cmd_ctx	 ctx;
	struct cmd_list	*cmdlist = NULL;
	int		 argc;
	char	       **argv, *cause;

	ctx.error = server_client_msg_error;
	ctx.print = server_client_msg_print;
	ctx.info = server_client_msg_info;

	ctx.msgdata = data;
	ctx.curclient = NULL;

	ctx.cmdclient = c;

	argc = data->argc;
	data->argv[(sizeof data->argv) - 1] = '\0';
	if (cmd_unpack_argv(data->argv, sizeof data->argv, argc, &argv) != 0) {
		server_client_msg_error(&ctx, "command too long");
		goto error;
	}

	if (argc == 0) {
		argc = 1;
		argv = xcalloc(1, sizeof *argv);
		*argv = xstrdup("new-session");
	}

	if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
		server_client_msg_error(&ctx, "%s", cause);
		cmd_free_argv(argc, argv);
		goto error;
	}
	cmd_free_argv(argc, argv);

	if (cmd_list_exec(cmdlist, &ctx) != 1)
		c->flags |= CLIENT_EXIT;
	cmd_list_free(cmdlist);
	return;

error:
	if (cmdlist != NULL)
		cmd_list_free(cmdlist);
	c->flags |= CLIENT_EXIT;
}

/* Handle identify message. */
void
server_client_msg_identify(
    struct client *c, struct msg_identify_data *data, int fd)
{
	int	tty_fd;

	c->cwd = NULL;
	data->cwd[(sizeof data->cwd) - 1] = '\0';
	if (*data->cwd != '\0')
		c->cwd = xstrdup(data->cwd);

	if (!isatty(fd))
	    return;
	if ((tty_fd = dup(fd)) == -1)
		fatal("dup failed");
	data->term[(sizeof data->term) - 1] = '\0';
	tty_init(&c->tty, tty_fd, data->term);
	if (data->flags & IDENTIFY_UTF8)
		c->tty.flags |= TTY_UTF8;
	if (data->flags & IDENTIFY_256COLOURS)
		c->tty.term_flags |= TERM_256COLOURS;
	else if (data->flags & IDENTIFY_88COLOURS)
		c->tty.term_flags |= TERM_88COLOURS;
	c->tty.key_callback = server_client_handle_key;
	c->tty.key_data = c;

	tty_resize(&c->tty);

	c->flags |= CLIENT_TERMINAL;
}

/* Handle shell message. */
void
server_client_msg_shell(struct client *c)
{
	struct msg_shell_data	 data;
	const char		*shell;

	shell = options_get_string(&global_s_options, "default-shell");

	if (*shell == '\0' || areshell(shell))
		shell = _PATH_BSHELL;
	if (strlcpy(data.shell, shell, sizeof data.shell) >= sizeof data.shell)
		strlcpy(data.shell, _PATH_BSHELL, sizeof data.shell);

	server_write_client(c, MSG_SHELL, &data, sizeof data);
	c->flags |= CLIENT_BAD;	/* it will die after exec */
}